Insulated electrical conductor for panel mounting

ABSTRACT

A panel mounted socket and insulating bushing assembly mountable entirely from one side of the panel. The bushing has an enlarged head to limit motion inwardly and an expandable section to grip the panel from the other side. The expandable part is expanded by inserting the socket. In one embodiment the bushing interior has radially inwardly extending projections having inclined planar surfaces which are pressed outwardly by insertion of the socket. The projections lock into an annular recess in the socket after assembly. In a second embodiment the bushing is elliptical and is deformed by insertion of a round socket. Mating flared parts and an annular retaining rim prevent inadvertent disassembly.

United States Patent 1191 Muz [ INSULATED ELECTRICAL CONDUCTOR FOR PANEL MOUNTING [75] Inventor: Edwin Muz, Uhlandstrasse, Germany [73] Assignee: Nicolay GmbH,Waiblingen,

Germany [22] Filed: Aug. 2, 1972 [21] Appl. No.: 277,268

[52] US. Cl. 339/126 RS, 339/22] R [51] Int.- Cl. l-I0lr 11/16 [58] Field of Search 339/221, 126,214, 128, 339/217 [56] References Cited UNITED STATES PATENTS 2,872,655 2/1959 Damon 339/126 RS X 2,918,521 12/1959 Abrams 339/94 A 2,948,773 8/1960 l-Iawes 339/126 RS X 3,292,132 12/1966 Murphy. 339/221 R X 3,349,365 10/1967 Dozier .1 339/221 R 3,745,510 7/1973 Mallon 339/14 R X Nov. 5, 1974 FOREIGN PATENTS OR APPLICATIONS 927,954 6/1963 Great Britain 339/59 M Primary Examiner-Richard E. Moore Attorney, Agent, or Firm-Roylance, Abrams, Berdo & Kaul 57 ABSTRACT A panel mounted socket and insulating bushing assembly mountable entirely from one side of the panel. The bushing has an enlarged head to limit motion inwardly and an expandable section to grip the panel from the other side. The expandable part is expanded by inserting the socket. In one embodiment the bushing inte- 1 Claim, 4 Drawing Figures INSULATED ELECTRICAL CONDUCTOR FOR PANEL MOUNTING This invention relates to a socket mounting apparatus and, more specifically; to an insulated bushing and socket assembly mountable in a panel from one side thereof.

It is common practice in instruments of various types to provide a socket at some portion of an electrical instrument, the socket being designed to receive a plug and, usually, being provided with means to receive an electrical wire or the like connecting the plug to the internal portions of the electrical apparatus. The socket is usually designed to receive a plug of a type having radial resilience, such as a plug of the banana type which has a split sleeve to make good electrical contact with the interior of the socket.

In mounting the socket in a wall or panel of an instrument wherein the instrument panel is made of an electrically conductive material, it is clearly necessary to provide an electrically non-conductive bushing surrounding the socket to perform the dual purposes of holding the socket in the panel and isolating it, electrically, from the panel. Generally, the exterior of the insulating body or some portion of the socket itself is externally threaded and is provided with an enlarged end or washer so that it can be inserted through a hole in the panel from one side and a nut can be attached to the member on the other side to hold the bushing in place. In order to install this type of socket access must be had to both sides of the receiving plate or panel and the assembly of this structure is relativelycumbersome and time-consuming.

An object of the present invention is to provide an instrument socket and bushing assembly which can be inserted in a simple manner through an opening in a receiving plate from one side of the plate.

'A further object is to provide a bushing to retain a socket in a panel, the bushing and socket being insertable from one side of the panel, and wherein the socket is retained in physically secure and electrically insulated relationship with the panel.

Broadly described, the invention includes an insulating body having a spreadable portion which can be enlarged radially outwardly by insertion of a plug socket in the center thereof, the insulating body having an enlarged end and a spreadable portion axially spaced from the large end at a distance approximately corresponding to the thickness of the receiving'plate, the

inner diameter of the spreadable portion being smaller, at least in selected regions. than the outer diameter of the cooperating socket portion. The assembly is such that the insulating body can be inserted through an opening in the panel provided for this purpose and the body is then fixed in the receiving plate by inserting the plug socket from the same side through the permanently enlarged end thereof, the insertion of the socket being the instrumentality for enlarging the spreadable portion of the body. The two portions are designed to have positively cooperating parts to secure the assembly in the panel and to prevent unintentional separation thereof. I

In order that the manner in which the foregoing and other objects are attained in accordance with the invention can be understood in detail, particularly advantageous embodiments thereof will be described with reference to the accompanying drawings, which form a part of the specification, and wherein:

FIG. 1 is a plan view, in partial section, of an apparatus according to the invention, mounted in a panel;

FIG. 2 is a vertical elevation of the apparatus of FIG.

FIG. 3 is a plan view, in partial section, of a second embodiment according to the invention; and

FIG. 4 is a front elevation of the apparatus of FIG. 3.

As shown in FIGS. 1 and 2, the bushing indicated generally at 10 includes an enlarged head portion 11 and a tubular sleeve portion 12, the exterior surface of the sleeve having the shape of a right circular cylinder in its relaxed state before being inserted through the opening 13 in a receiving wall or panel 14 which is provided to receive the bushing. The interior surface of the bushing is approximately in the shape of a right circular cylinder in the relaxed condition but is provided with a plurality of radially inwardly extending projections or studs 15, each stud having a gently sloping surface 16 forming a rather small acute angle with the interior surface of the sleeve, and a substantially radial surface 17, substantially perpendicular to the interior surface of the sleeve.

It will be observed that the distance between the surface 18 of enlarged head 11 which is intended to abut the outer face of panel 14 and the initiation of each stud l5 approximates the thickness of the panel through which the bushing is to be inserted.

A socket indicated generally at 20 designed to coopcrate and form an integral assembly with bushing 10 includes a cylindrical body 21 having an annular recess 22 approximately midway between the ends of the body. An axial bore 23 extends inwardly from one end of the body, the other end of the body being closed. Bore 23 is designed to receive a conventional electrical plug and is dimensionedfor that purpose, the open end of bore 23 being chamfered at 24 to facilitate entry of the plug. The closed end of body 21 can be provided with a lug or tab 25 having an opening 26 to receive a soldered or threaded electrical connection in a wellknown manner.

It will be observed that the bushing 10 is constructed I from a good electrical insulating material which is formed as an integral whole, including studs 15, and is further characterized by some resilience or elasticity while body 21 is made of a good electrical conductor which will resist the effects of corrosion such as, for example, brass.

The above described apparatus is assembled by first providing an opening in panel 14 of approximately the outer diameter of that portion of sleeve 12 adjacent the enlarged end 11. The sleeve portion of the bushing is then inserted through the opening and held in place while body 21 is inserted from the same side of the panel through enlarged portion 11. The exterior surface of the inner end of body 21 presses against the gently sloping surfaces 16 of studs 15, causing the portion of the sleeve adjacent the studs to radially enlarge to permit the larger portion of body 21 to pass. As soon as the first portion of recess 22 reaches surfaces 17 of studs 15 the sleeve again contracts due to its natural elasticity until the studs come in contact with the exterior surface of the anular recess. The sleeve is then permitted to remain in this position, retaining the socket against movement in the reverse direction out of the assembly.

It will be observed that the outer diameter of the reduced portion of 22 of body 21 is greater in diameter than the .relaxed inner diameter of the circle defined by the innermost points of studs 15. Thus, that portion of sleeve 12 which rests on the opposite side of the panel from enlarged head 11 remains somewhat enlarged and distorted from the shape it had before insertion of body 21. This prevents the bushing from being inadvertently removed from the panel.

It will also be observed that the axial dimension of annular recess 23 can be selected to be approximately the same length as studs 15 so that the studs effectively prevent axial movement of body 21 in either direction. The mounting of the bushing and socket as previously described can be accomplished by hand or by a tool such as a compressed air tool.

It will be seen that FIG. 2 illustrates bushing before the socket has been installed, and clearly shows the radially inwardly projecting studs and surfaces 16 against which the first inserted end of socket 21 acts. It will also be observed that enlarged head 11 has a square shape in the specific embodiment shown.

A further embodiment according to the invention is illustrated in FIGS. 3 and 4. As in the case of the first embodiment, the bushing includes an enlarged head portion 30 having a surface 31 disposed to abut the outer surface of panel 14, and a sleeve portion 32 which extends axially from the head portion. Also, the bushing is provided with a bore which extends axially therethrough. However, the interior and exterior surfaces of the bushing are somewhat differently formed. Sleeve portion 32 is provided with a section 33 of sub stantially uniform wall thickness and a portion 34 wherein the wall thickness is significantly enlarged. The axial lengthof the uniform portion 33 is approximately equal to the thickness of panel 14. Additionally, the sleeve portion is formed in an elliptical shape, as shown in FIG. 4, wherein the largest (major) inside diameter of the sleeve is approximately equal to the outside diameter of the plug socket-which is intended to be inserted therethrough, while the smaller (minor) diameter thereof is somewhat smaller than the exterior of the socket. Additionally, the smallest outside diameter of the bushing is selected to approximately equal the diameter of the opening through which the bushing is to be inserted so that the larger diameter thereof normally causes constriction in the opening.

The enlarged head portion includes a frustroconical surface 35 which constitutes an outward flaring from the average diameter of the sleeve interior and areverse frustroconical surface 36 which causes there to exist an inwardly directed lip portion. These surfaces are designed to firmly retain the socket therein.

The socket includes a substantially cylindrical body portion 38 and a frustroconical outwardly flaring head portion 39,- the outer surface of which is designed to substantially mate with the interior surface of the enlarged head portion of the bushing. The socket has an interior bore 40 which also flares outwardly at 41 following the contour of the exterior surface. The socket is also provided with an electrical lug or tab 42 for receiving an electrical connection.

In the assembly of these structures, the insulating body is first inserted in the opening provided in panel 14 and tends to hold itself therein because of the elliptically shaped sleeve. Then, body 38 is inserted into the bore through the bushing and distorts the elliptical sleeve to conform to the circular shape of the body. Upon further insertion the cone-shaped portion of the socket deforms the inwardly extending rim 36, causing it to expand to admit the flared portion of the socket, which, upon passage, again resumes its original shape and prevents the socket from again withdrawing.

As shown in FIG. 4, the bushing in its related condition exhibits an elliptical shape in the interior of the sleeve and in the outer opening.

A practical embodiment of the invention includes a bushing having an enlarged portion in the shape of a square of about I 1 millimeters on a side, the thickness of the enlarged portion in the axial direction being approximately 4 millimeters. The entire length of the insulating body is about I I millimeters. The plug socket typically has an outside diameter of about 6 millimeters and alength, excluding the electrical connecting tab or lug, of about 19 millimeters. The connecting member is typically approximately 7 millimeters long, these general dimensions being the-same for the embodiments in all of FIGS. l-4. As will be recognized, the drawings are given by way of example and are slightly distorted relative to the practical form of the invention as above described.

While certain advantageous embodiments have been chosen to illustrate the invention it will be understood by those skilled in the art that various changes and modifications can be made therein without departing from the scope of the invention as defined in the appended claims.

What is claimed is:

1. An electrical connector assembly for panel mounting, the connector being of the type having an electrically conductive connector member and an electrically nonconductive sleeve member which surrounds and electrically isolates the connector member from the panel, the improvement comprising the combination of a sleeve member including a head portion having a surface for abutting the panel, and a tubular porsion of said radially expandable sectionso that insertion of said connector member causes said section to expand,

said sleeve member and said connector member being provided with means for retaining the assembly in assembled condition including an annular recess in the outer surface of said connector member and a plurality of radially inwardly extending projections disposed to'engage said recess,

said recess and projection being disposed to engage when the members are assembled. 

1. An electrical connector assembly for panel mounting, the connector being of the type having an electrically conductive connector member and an electrically nonconductive sleeve member which surrounds and electrically isolates the connector member from the panel, the improvement comprising the combination of a sleeve member including a head portion having a surface for abutting the panel, and a tubular portion insertable through an opening in the panel, said tubular portion having a radially expandable section axially spaced from said head portion a distance approximating the desired panel thickness, and a connector member having a cylindrical outer surface, the outer diameter of at least part of said connector member being larger than the inner dimension of said radially expandable section so that insertion of said connector member causes said section to expand, said sleeve member and said connector member being provided with means for retaining the assembly in assembled condition including an annular recess in the outer surface of said connector member and a plurality of radially inwardly extending projections disposed to engage said recess, said recess and projection being disposed to engage when the members are assembled. 